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Structures · Algebra

DivisionSemiring

A DivisionSemiring is a Semiring with multiplicative inverses for nonzero elements. An instance of DivisionSemiring K includes maps nnratCast : ℚ≥0 → K and nnqsmul : ℚ≥0 → K → K. Those two fields are needed to implement the DivisionSemiring K → Algebra ℚ≥0 K instance since we need to control the specific definitions for some special cases of K (in particular K = ℚ≥0 itself). See also note [forgetful inheritance]. If the division semiring has positive characteristic p, our division by zero convention forces nnratCast (1 / p) = 1 / 0 = 0.

Defined in
Mathlib.Algebra.Field.Defs
Shape
One type argument · adds div_eq_mul_inv, zpow_zero', zpow_succ', zpow_neg', inv_zero, mul_inv_cancel, nnratCast_def, nnqsmul, nnqsmul_def

Extends3

Extended by2

Forgetful instances

Provided automatically by

Concrete types that are instances7

  • Filter.Germ
  • DirectLimit
  • OrderDual
  • ULift
  • MulOpposite
  • Lex
  • AddOpposite

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Assumed by266

Ancestors59